Stator mounting for flywheel magneto



y 1958 A. L. HOFMANN 2,835,833 7 STATOR MOUNTING FOR FLYWHEEL MAGNETO Filed Sept. 16, 1955 INVENTOR. ALFRED L HUI-MANN JQMM A T TQRNE Y United States Patent Oflice STATOR MOUNTING FOR FLYWHEEL MAGNETO Alfred L. Hofmann, Cedarburg, Wis., assignor to Kickhaefer Corporation, Cedarburg, Wis., a corporation of Wisconsin Application September 16, 1955, Serial No. 534,768

4 Claims. (Cl. 310-153) This invention relates generally to magneto stator mountings and more specifically to an improved fastening means for :adjustably holding a stator plate of a flywheel magneto to a pilot flange of a crankcase of an internal combustion engine in such a manner that ,the stator plate may be manually moved to, and frictionally held in, various positions of angular adjustment on the pilot flange.

The invention is desirable for use with the stator plate of a flywheel magneto, which is to be used on an engine of the variable spark type, as distinguished from the fixed spark Ftype. Such a plate, and the stationary magnetic coil carrying elements of the magneto mounted thereon, must be movable to various angular positions relative to the engine crankshaft in order to vary the timing of "the spark produced by the magneto. An outboard motor is one example of an engine of the type described.

It is therefore an object of the present invention to provide an improved fastening means for holding the stator plate of a flywheel magneto to a pilot flange on the crankcase of an internal combustion engine that is simple in design and inexpensive in construction.

Another object of the invention is the provision of a fastening means for adjustably holding the stator plate of a flywheel magneto to a pilot flange on the crankcase of an internal combustion engine that is easily accessible for adjustment without necessitating the removal of the flywheel.

Still another "object of the invention is to provide fastening means for adjustably holding the stator plate of a flywheel magneto to a pilot flange on the crankcase of an internal combustion engine wherein only one initial adjustment is necessary regardless of the number of times the stator plate is thereafter removed from and replaced on the pilot flange.

Objects and advantages other than those set forth above will be apparent from the following description when read in connection with the accompanying drawing, in which:

Fig. 1 is an elevation view in section of a flywheel magneto embodying the fastening means of this invention; 1

' Fig. 2 is a bottom plan view of Fig. 1;

Fig. 3 is a plan view showing the spring clamp by which the statorplate is adjustably fastened to the pilot flange; and

Fig. 4 is a view in section taken along line 4-4 of Fig. 3.

Referring to the drawings, a magneto 1 is shown mounted on a pilot flange 2 having a cylindrical peripheral surface 3 and outer and inner end faces 4, 6 respectively which are normal to the axis of the cylindrical surface 3. The pilot flange 2 is provided on the upper end of a crankcase hub 7 of an engine, not shown, and the hub carries a bearing 8 for journaling a crankshaft 9. An annular stator plate 11 is mounted on the pilot flange 2 and has an inner cylindrical wall 12 mating with 2 the cylindrical surface 3 of the pilot flange 2. A pair of ribs 13 project inwardly from and are carried by the stator plate 11 to provide support means for the stator plate when the ends of the ribs 13 engage the outer end face 4 of the pilot flange 2. A handle 14 of the usual type is mounted to the stator plate 11 by means of screws 16 and extends radially outward beyond the outer periphery of the stator plate 11 to provide means for angularly moving thestator plate 11 relative to the pilot flange 2.

The stator 11 provides a base for the electrical elements designated at 17 of the magneto 1 which inoperation provides a high tension spark for the spark plugs of the engine as is well known in the art. Since the invention is concerned with the fastening of the stator plate 11 to the pilot flange 2 of the engine crankcase 7 and not dependent upon the construction and arrangement of the magneto, the elements designated at 17 will not be described in detail. A flywheel 18 comprising a downwardly dished member has an axial bore through which a threaded end of the crankshaft 9 extends and is mounted thereto by means of a nut 19. The rim 21 of the flywheel 18 slidably engages a circular peripheral rim 22 of the stator plate 11 to form an enclosure for the magneto 1.

The fastening means of the invention comprises a spring clamp member 23, of which two are shown although any number may be used, constructed of a suit-.

able material such as spring steel having properstrength' and flexure characteristics. The spring clamp 23 has a projection extending from the body portion 26 shown as a substantially circular spring loop 24 at one end of the clamp to provide a transverse opening therein large enough for a purpose to be explained hereinafter. The opposite end of the spring clamp member 23 is provided with transversely projecting arms 28 having cam ends 29. An elongated slot 31 is provided in the body portion 26 of the spring member 23 intermediate the ends thereof. The spring clamp 23 is mounted to the stator plate 11 by means of a screw 32 passing through the elongated slot 31 and engaging a tapped opening 33 provided in the stator plate 11.

Before mounting the stator plate 11 to the pilot flange 2, each spring clamp member 23 is assembled to plate 11 by partially engaging the screw 32, which extends through slot 31 of the clamp, into the tapped opening 33 with the spring clamp disposed in a radially extended position as permitted by the slot 31 so that the cam ends 29 of the clamp member 23 will clear the flange 2 and with the loop 24 disposed outwardly of the rim 22 of the stator plate 11. The magneto 1 is then placed upon the pilot flange 2 with the cylindrical wall 12 of the stator plate 11 mating with the cylindrical surface 3 of the pilot flange 2 and the ribs 13 engaging the outer end face 4. The stator plate 11 is then fastened to the pilot flange 2 by moving each of the spring clamp members 23 radially inwardly until the loop 24 seats within a narrow, inverted V-shaped groove 34 provided in the stator plate 11 near the peripheral rim 22 thereof and on a radial line through the opening 33. position the cam ends 29 of the arms 28 are in engag ment with the inner end face 6 of the pilot flange 2. The groove 34 prevents radial movement of the clamp member 23 and is provided with side portions 36 which in conjunction with the screw 32 prevents lateral or transverse movement of the clamp member 23. The screw 32 is turned to move inwardly into the tapped opening 33 forcing the body 26 of the clamp member 23 toward the stator plate 11 flexing the clamp member 23 and causing the cam ends 29 to exert a pressure against the inner end face 6. After the screw 32 has been turned far Patented May 29, 1958 In this operative enough inwardly to establish a desired frictional pressure of the cam ends 29 against the inner end face 6 of the flange 2 to adjustably hold the stator plate 11 to the pilot flange, the screw 32 may be locked in that position by means of a lock nut 37. The screw 32 need not be tampered with thereafter regardless of the number of times "the stator plate 11 is removed from or replaced on the pilot flange 2 except for changing the frictional pressure exerted by the clamp member 23 on the pilot flange.

Removal of the magneto 1 and stator plate 11 from the pilot flange 2 after the screw 32 has been locked in the proper position may be accomplished by moving the clamp member 23 into an inoperative position by placing a finger in the loop 24 of the spring clamp 23 and applying a radially outwardly directed force thereto to remove the loop 24 from the groove 34 past the peripheral rim 22 of the stator plate 11. With the loop 24 no longer supported by the stator plate 11, the clamp member 23 becomes unflexed and the arms 28 and cam ends 29 release their pressure upon the inner end face 6 of the pilot flange 2. The spring clamp 23 may be moved outwardly until the cam ends 29 clear the pilot flange 2 for removal of the magneto 1 and stator plate 11. To facilitate removal of the spring clamp 23, the stator plate 11 is provided with a nipple 38 laterally spaced from the loop 24 of the spring clamp 23 and in substantial register therewith to provide a fulcrum for one end of a screw driver or similar tool, not shown, insertable through the loop 24. Pressure exerted outwardly upon the other end of the tool readily removes the loop 24 of the clamp member 23 from the groove 34. To refasten the stator plate 11 and magneto 1 to the pilot flange 2, it is only necessary to position the stator plate 11 on the flange 2 and to apply pressure radially inwardly on the loop 24 of the spring clamp 23 to force the loop 24 into the groove 34.

Although but one embodiment has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications of the invention maybe made therein without departing from the spirit of the invention or from the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. Fastening means for adjustably holding the stator plate of a flywheel magneto to the pilot flange of an engine crankcase, comprising in combination, a clamp means having outwardly projecting arms provided with cam ends at one end thereof and the other end of said clamp means forming a substatially circular spring loop, said clamp means having an elongated slot intermediate said ends, said stator plate having along a radial line thereof a tapped opening and a substantiallyV-shaped groove adjacent the periphery thereof, a screw insertable through said slot adapted to threadingly engage said tapped opening to adjustably mount said clamp means on said stator plate in an operative position with said cam ends engaging said pilot flange and said loop seating within said groove, said screw being threadingly adjusted in said operative position so that said cam ends exert a desired frictional pressure against said pilot flange and the spring loop against said stator plate to adjustably hold said stator plate to said pilot flange, lock means for immovably securing said screw in said operative position, and said clamp means adapted to be radially moved into an inoperative position with said cam ends out of engagement with said pilot flange and said loop unseated from said groove in the stator plate and extending radially outwardly past said periphery of said stator plate whereby said stator plate may be removed from said pilot flange.

2. The combination of claim 1 wherein said stator plate is provided with a nipple laterally spaced from said loop and radially spaced from the axis of said pilot flange substantially the same distance as said loop to facilitate removing said clamp means from said operative position to said inoperative position by means of a tool.

3. Fastening means for adjustably securing an outwardly disposed stator plate of a flywheel magneto against movement relative to the pilot flange of an engine crankcase, comprising a spring clamp member having a body portion and radially extending end portions with the inner end portion engaging the underside of the pilot flange and the outer end portion engaging the underside of the stator plate, said end portions being adapted to maintain the body portion of the clamp member out of contact with the pilot flange and stator plate in the operative position of the member and said body portion having a radially extending slot, and mounting means extending upwardly through the slot and received by the stator plate to secure the clamp member in an operative position wherein said member is flexed upwardly intermediate the ends thereof to provide desired spring pressure between the ends of the member and the stator plate and pilot flange, respectively, to secure the plate and flange against relative movement, said clamp member being adapted to move radially outward to an inoperative position in response to a radially directed force with the slot moving relative to the mounting means and the inner end portion of said member moving out of engagement with the pilot flange to permit relative adjustment between the stator plate and pilot flange, and, after adjustment, said clamp member being adatped to be moved radially inward relative to the mounting to return to the operative position securing the stator plate with respect to the pilot flange. v

4. Fastening means for adjustably securing an outwardly disposed stator plate of a flywheel magneto against movement relative to the pilot flange of an engine crankcase, with the stator plate being provided with a radially extending groove in the underside thereof adjacent to the outer periphery, comprising a spring clamp member extending radially between the stator plate and the pilot flange and having laterally spaced cam ends at the inner end thereof adapted to engage the underside of the pilot flange and having an upwardly projecting loop at the outer end thereof adapted to seat in the groove provided in the stator plate, said cam ends and loop maintaining the remainder of said clamp member out of contact with the pilot flange and stator plate in the operative clamping position of the member and said member having a radially extending slot intermediate the ends thereof, and adjustable mounting means extending upwardly through the slot and received by the stator plate and being adjusted to flex the clamp member upwardly intermediate the ends thereof to provide desired spring pressure between the loop and the stator plate and the cam ends and the pilot flange to secure the plate and flange against relative movement, said loop providing means whereby the clamp member may be moved radially with respect to the mounting means to an inoperative position with the loop disengaged outwardly from the groove in the stator plate and the cam ends out of engagement with the pilot flange and thereafter back again to the operative position without further adjustment of said mounting means.

References Cited in the file of this patent UNITED STATES PATENTS 1,613,033 Hawkins Jan. 4, 1927 2,487,095 Brownlee Nov. 8, 1949 2,569,461 Dingman Oct. 2, 1951 

